Field of the Invention
The present invention relates to an internal combustion engine, and more particularly, to an engine having a water jacket in which a block water jacket is divided into upper and lower parts and cooling water flowing through the upper part of the block water jacket flows from the exhaust side of a head water jacket to the intake side to form a cross-flow.
Description of Related Art
In general, water-cooled engines are cooled by pumping cooling water from a water pump to a water jacket inside a cylinder block and a water jacket inside a cylinder head.
Since the water pump is installed on the cylinder block, cooling water pumped from the water pump is fed first to the water jacket inside the cylinder block and then guided to the water jacket inside the cylinder head.
The cylinder head gets hot easily because it forms a combustion chamber—especially, around an exhaust port due to the circulation of combustion gases. In this regard, cooling water passages from the water jacket in the cylinder block are installed around the exhaust port in the cylinder head, in order to improve the cooling performance around the exhaust port.
Recently, there has been introduced a structure that improves the cooling efficiency of cooling water by separating the water jackets in the cylinder head and cylinder block into a head water jacket and a block water jacket and controlling cooling water fed to the head and block water jackets, and that reduces fuel consumption by individually controlling the temperatures in them.
There was introduced another structure that actively cools a high-temperature part in the exhaust port (exhaust side) using a cross-flow design that allows cooling water flowing through the head water jacket in the cylinder head to flow from the exhaust side to the intake side, and that reduces fuel consumption and improves cooling efficiency by blocking the flow of cooling water to the block water jacket in the cylinder block in a low-temperature condition.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.